Your question as I understand it is that you have capital gains and want to claim an expense for a product to lower your tax liability. You have two separate transactions. Capital gains are reduced by capital losses. If no capital losses you will show in your income tax the capital gain. The the other transaction you site is selling products to deduct against the gain. I think this is mixing apples and oranges. If you have a business and you sell a product that will be an expense, but you will also have the income from the sale of the product.
